Printed circuit boards are now almost universally used. A variety of devices and methods are used to connect these boards together. Some include direct wiring with cables such as ribbon cables while others use a plug and socket technique. In the latter the socket is usually permanently attached to a "motherboard" (i.e. a main circuit board) or chassis and the printed circuit board is provided with a plug mounted on one edge called an "edge connector." The printed circuit board (printed circuit board) is installed by simply plugging the printed circuit board edge connector into the socket provided on the main circuit board or chassis.
Plugs on these printed circuit boards exist in various forms. One type of plug is comprised of a plurality of pins mounted in a connector block. The plug is attached to the board by soldering one end of the pins in the plug to printed circuit board pads that surround holes in the board. The other end of the pins plug into a main circuit board or chassis socket.
Another type of known plug is comprised of a plurality of printed circuit board strips terminating at a flange or extension of the printed circuit board itself. These are sometimes called "card edge connectors".
In each of these cases the electrical connection is made by a male pin of printed strip that is being inserted into a metal lined connecting socket. Typically, the metal connectors in the socket make a close tolerance fit, and include a resilient leaf spring type arrangement adapted to maintain good electrical contact with the male pin connections.
In most cases the above-described arrangement is adequate but does have some problems. A significant problem is the accessibility of the board for troubleshooting or for in-circuit testing. When installed, one side of the board will typically be accessible while the other is not. In some cases neither side is very accessible. The solution usually is to unplug and remove the board for circuit testing. This is not an entirely satisfactory alternative because actual circuit conditions are sometimes difficult to simulate. Ideally, all parts of a circuit board should be accessible without removing the board from the circuits. One way to do this is by extension cables which allow the board to be remotely connected. However this requires maintaining a large supply of extension cables, at considerable expense. Even this may not be enough, because the particular cable needed might not be available or the available cable might be too short.
Another difficulty with present printed circuit board connectors is their deteriorated conductivity after long periods of use. Corrosion creeping into the interface between the male and female contacts often interferes with or intermittently interrupts operations. The former is more feared than the latter, because intermittent problems are sometimes the most difficult to find. Further, any contact corrosion is troublesome in the low voltage digital circuits now in use.
Electrical contact sometimes also deteriorates because the spring biased contacts lose their resilience after long periods of use. Corrosion can sometimes be easily corrected by spraying with a contact cleaner, but spring biased contacts which lose their resiliency rquire difficult and costly connector replacement.
It is therefore an object of the present invention to provide an electrical connector which improves in-circuit accessibility to printed circuit boards.
Yet another object of the present invention is to provide a separable connector which improves accessibility and removability of a printed circuit board.
Still another object is to provide a separable connector having a barrel-shaped cylindrical contact area fitting a chassis or main circuit board mountes socket which has latches to secure the printed circuit board connector to allow a printed circuit board to swivel for easy access to all parts of the board while still remaining connected. The latches also firmly hold the separable connector together, keeping electrical conducting surfaces always in good firm contact.